Full-width/half-width issues

I wonder whether the simpler and more general approach would be to
apply canonical decompositions to the internationalized address before
dequoting?

This would remove having to worry about full-width at, full-width
quote, etc, and would seem to have no effect on the subsequent
processing of the domain by IDNA.

This would also have the effect that parenthesized characters (such as
U+2474) would be mapped to sequeneces that might be treated as
comments.  I'm not sure whether this would be good are bad (but see
below).

However, if we have to worry about whitespace, then we have to worry
about whether we should keep the (2)822 definition of whitespace, or
generalize it to all whitespace chars.  (The draft generalizes it only
to full-width space).  One approach that would avoid the issue
entirely would be to require non-traditional addresses to avoid using
the obsolete syntax of 2822.  This would avoid any use of unquoted
whitespace in a non-traditional addr-spec.

(If the requirement was that the address avoided the use of obsolete
syntax after canonical decompositions were applied, this would also
prohibit the unquoted use of characters such as parenthesized digits.)

	-roy